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//===-- esan.cpp ----------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of EfficiencySanitizer, a family of performance tuners.
//
// Main file (entry points) for the Esan run-time.
//===----------------------------------------------------------------------===//
#include "esan.h"
#include "esan_interface_internal.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flag_parser.h"
#include "sanitizer_common/sanitizer_flags.h"
// See comment below.
extern "C" {
extern void __cxa_atexit(void (*function)(void));
}
namespace __esan {
bool EsanIsInitialized;
ToolType WhichTool;
static const char EsanOptsEnv[] = "ESAN_OPTIONS";
// We are combining multiple performance tuning tools under the umbrella of
// one EfficiencySanitizer super-tool. Most of our tools have very similar
// memory access instrumentation, shadow memory mapping, libc interception,
// etc., and there is typically more shared code than distinct code.
//
// We are not willing to dispatch on tool dynamically in our fastpath
// instrumentation: thus, which tool to use is a static option selected
// at compile time and passed to __esan_init().
//
// We are willing to pay the overhead of tool dispatch in the slowpath to more
// easily share code. We expect to only come here rarely.
// If this becomes a performance hit, we can add separate interface
// routines for each subtool (e.g., __esan_cache_frag_aligned_load_4).
// But for libc interceptors, we'll have to do one of the following:
// A) Add multiple-include support to sanitizer_common_interceptors.inc,
// instantiate it separately for each tool, and call the selected
// tool's intercept setup code.
// B) Build separate static runtime libraries, one for each tool.
// C) Completely split the tools into separate sanitizers.
void processRangeAccess(uptr PC, uptr Addr, int Size, bool IsWrite) {
VPrintf(3, "in esan::%s %p: %c %p %d\n", __FUNCTION__, PC,
IsWrite ? 'w' : 'r', Addr, Size);
if (WhichTool == ESAN_CacheFrag) {
// TODO(bruening): add shadow mapping and update shadow bits here.
// We'll move this to cache_frag.cpp once we have something.
}
}
static void initializeFlags() {
// Once we add our own flags we'll parse them here.
// For now the common ones are sufficient.
FlagParser Parser;
SetCommonFlagsDefaults();
RegisterCommonFlags(&Parser);
Parser.ParseString(GetEnv(EsanOptsEnv));
InitializeCommonFlags();
if (Verbosity())
ReportUnrecognizedFlags();
if (common_flags()->help)
Parser.PrintFlagDescriptions();
__sanitizer_set_report_path(common_flags()->log_path);
}
void initializeLibrary(ToolType Tool) {
// We assume there is only one thread during init.
if (EsanIsInitialized) {
CHECK(Tool == WhichTool);
return;
}
WhichTool = Tool;
SanitizerToolName = "EfficiencySanitizer";
initializeFlags();
// Intercepting libc _exit or exit via COMMON_INTERCEPTOR_ON_EXIT only
// finalizes on an explicit exit call by the app. To handle a normal
// exit we register an atexit handler.
::__cxa_atexit((void (*)())finalizeLibrary);
VPrintf(1, "in esan::%s\n", __FUNCTION__);
if (WhichTool != ESAN_CacheFrag) {
Printf("ERROR: unknown tool %d requested\n", WhichTool);
Die();
}
EsanIsInitialized = true;
}
int finalizeLibrary() {
VPrintf(1, "in esan::%s\n", __FUNCTION__);
if (WhichTool == ESAN_CacheFrag) {
// FIXME NYI: we need to add sampling + callstack gathering and have a
// strategy for how to generate a final report.
// We'll move this to cache_frag.cpp once we have something.
Report("%s is not finished: nothing yet to report\n", SanitizerToolName);
}
return 0;
}
} // namespace __esan
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